Computing devices may utilize graphic user interfaces to present content and allow for interaction with such presented content. As computing devices become smaller, it becomes more difficult to efficiently present content and provide intuitive mechanisms for interacting with such presented content.
A variety of compact computing devices, such as some smart phones and tablet devices, include a touch-screen display. The touch screen permits users to use gestures with an object, such as a finger, to interact with the computing device. For example, using a touch screen, the user may navigate through emails, documents, web pages, and other media. An example of such a computing device includes the iPhone® of Apple, Inc. of Cupertino, Calif., which permits users, for example, to scroll through a list of items with a swiping gesture, and to zoom in and out of a view with a pinching/de-pinching gesture.
However, a problem with conventional touch screen devices is that they do not provide an efficient way for a user to navigate structured documents, or media having different viewing modes or levels of detail. As one example, conventional user interfaces for touch screen devices include a “back” button to navigate to a previous viewing mode or level of detail, wasting precious screen real estate. Here, by “structured document,” we mean a general store of data that has some form of organization. We will elaborate further on this in the detailed description below.
As another example, when using gestures to navigate to different viewing modes of a document, for example scrolling a list or zooming an image, conventional touch screen devices do not provide a feedback mechanism requiring the user to exert additional effort when crossing a section or other internal threshold of the document.
Additionally, existing user interfaces for touch screen devices have only limited input commands for changing view modes. As a result, there are difficulties in using conventional user interfaces to change view modes for more complex situations.